this adds the screenreader-only text "interpreted as" to the start of
the JME preview box. Both the box and the MathJax part are marked as
aria-live="polite" - need to test with a screenreader to establish if
this is right. I don't think it's helpful to keep reading out
"interpreted as" each time the maths changes, but it's needed when
reading through the page, to separate it from the input box.
this adds the screenreader-only text "interpreted as" to the start of the JME preview box. Both the box and the MathJax part are marked as aria-live="polite" - need to test with a screenreader to establish if this is right. I don't think it's helpful to keep reading out "interpreted as" each time the maths changes, but it's needed when reading through the page, to separate it from the input box.
see #831